Which anthelmintic agent works by blocking neuromuscular activity in parasites?

Pyrantel Pamoate acts by interfering with the neuromuscular junction in parasites, leading to paralysis and expulsion of the worms from the host's body. It is classified as a depolarizing neuromuscular blocker, which causes the nematodes to become paralyzed, preventing them from maintaining their attachment to the intestinal wall. This action allows the body's natural peristalsis to effectively remove the parasites from the gastrointestinal tract.

In contrast, the other agents listed function through different mechanisms. Praziquantel works by increasing the permeability of the parasite's cell membrane to calcium ions, leading to muscle contraction and paralysis, eventually causing the worm to be dislodged. Albendazole disrupts the microtubule formation inside the parasite, inhibiting essential metabolic processes. Ivermectin, on the other hand, operates mainly by binding to glutamate-gated chloride channels, which leads to paralysis and death of certain parasites. Each of these agents has its unique mode of action, but it is Pyrantel Pamoate's specific ability to block neuromuscular activity that distinguishes it clearly as the correct option in this context.